[size=12] [/size My vitara is a 98 lx 8 valve 1600 with single point injection. Andwith 12,000 on the clock,
Is it normal to get a pressure build up in the fuel tank ? As when the the fuel cap is released a whoosh of air blows out. Does anybody know why ? Also fuel consumption is high ,about 200 to a tank full. The car is not modified in anyway.
Can anyone suggest any improvements as I am sure a v6 lump would be more economical

Thanks for the prompt reply DavidS just wondered what is causing this pressure ,the charcoal canister is under a vacumn from the engine manifold . The pressure side of the pump does not return to the tank as far as I am aware and it can't be air temperature. The only pressure on the fuel system is from the pump ?????

The tank is also under vacume, so it should be air going in you hear, not coming out. This is done through the charcoal filter, the vapour or fumes are then sent into the engine and burnt, not vented into the ozone layer. Check it!
Dennis